Contacts of the helix formed by residues 321 - 325 (chain D) in PDB entry 4IRQ


Residue contacts within the protein are derived with the CSU software (Sobolev V., Sorokine A., Prilusky J., Abola E.E. and Edelman M. (1999) Automated analysis of interatomic contacts in proteins. Bioinformatics, 15, 327-332). A short description of the analytical approach is given at the end of the page.
For CSU analysis of other PDB entry

Note:
Non-standard 3 letter residue codes indicate a heterogroup. To identify and analyse, use LPC software

Legend:
Dist - nearest distance (Å) between atoms of two residues
Surf - contact surface area (Å2) between two residues
HB   - hydrophilic-hydrophilic contact (hydrogen bond)
Arom - aromatic-aromatic contact
Phob - hydrophobic-hydrophobic contact
DC   - hydrophobic-hydrophilic contact (destabilizing contact)
+/-  - indicates presence/absence of a specific contacts
*    - indicates residues forming contacts  by their side chain
       (including CA atoms)
Residues in contact with THR 321 (chain D).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    220D  ARG*     3.8    37.2    -      -       +      +
    222D  TRP*     3.3    19.4    +      -       -      -
    316D  CYS*     3.5     5.5    -      -       -      -
    317D  ASP*     3.0    15.8    +      -       -      +
    320D  ALA*     1.3    87.6    -      -       +      +
    322D  PRO*     1.3    59.8    -      -       -      +
    323D  TRP*     3.1    37.3    +      -       +      -
    324D  CYS*     3.4    17.0    +      -       -      -
----------------------------------------------------------
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Residues in contact with PRO 322 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    271D  ILE*     5.6     2.9    -      -       -      +
    273D  ALA*     6.2     1.8    -      -       +      -
    318D  LYS*     3.2    28.8    -      -       +      +
    319D  THR*     4.2     6.5    -      -       -      +
    320D  ALA      3.7     5.4    -      -       -      +
    321D  THR*     1.3    83.4    -      -       -      +
    323D  TRP*     1.3    76.2    +      -       +      +
    324D  CYS*     3.1    10.1    +      -       -      -
    325D  THR*     3.8    14.7    +      -       -      +
    326D  PHE*     6.0     0.2    -      -       -      +
----------------------------------------------------------
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Residues in contact with TRP 323 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    138D  ARG*     3.0    28.1    +      -       -      +
    220D  ARG*     2.9    42.8    +      -       +      -
    221D  PHE*     4.8     0.2    -      -       -      +
    222D  TRP*     3.5    19.6    -      +       +      +
    271D  ILE*     4.1    20.6    -      -       +      +
    272D  ALA*     6.3     0.2    -      -       +      -
    273D  ALA*     4.3     8.3    -      -       +      -
    274D  GLN*     3.6    61.5    -      -       +      +
    277D  GLU*     3.6    39.0    -      -       +      -
    320D  ALA      3.8     7.2    -      -       -      -
    321D  THR*     3.6    20.2    -      -       +      -
    322D  PRO*     1.3    95.6    -      -       +      +
    324D  CYS*     1.3    57.8    +      -       -      +
    325D  THR      3.4     3.4    -      -       -      -
----------------------------------------------------------
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Residues in contact with CYS 324 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    137D  PHE*     3.7    10.6    -      -       +      -
    138D  ARG*     2.9    32.9    +      -       -      +
    222D  TRP*     3.5    31.0    -      -       +      -
    316D  CYS*     2.0    49.8    -      -       +      -
    318D  LYS*     3.6    10.3    -      -       -      -
    321D  THR      3.4     7.9    +      -       -      +
    322D  PRO      3.1     2.2    -      -       -      -
    323D  TRP*     1.3    79.1    -      -       -      +
    325D  THR*     1.3    72.0    +      -       -      +
----------------------------------------------------------
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Residues in contact with THR 325 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    136D  HIS      5.9     1.3    -      -       -      +
    137D  PHE*     4.3    13.8    -      -       +      +
    138D  ARG*     3.6     7.4    +      -       -      +
    271D  ILE*     3.8     9.5    -      -       -      +
    318D  LYS*     3.5    28.4    -      -       +      +
    322D  PRO      3.8     7.7    +      -       -      -
    323D  TRP      3.4     1.5    -      -       -      +
    324D  CYS*     1.3    86.5    -      -       -      +
    326D  PHE*     1.3    77.2    +      -       -      +
    327D  SER      3.1    10.5    +      -       -      +
----------------------------------------------------------
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A short description of the analytical approach
The contact analysis used in this page is based upon the approach developed in: Sobolev V., Wade R.C., Vriend G. and Edelman M. PROTEINS (1996) 25, 120-129. Contact legitimacy depends on the hydrophobic-hydrophilic properties of the contacting atoms. In order to define it, for each inter-atomic contact, eight atom classes have been introduced:


   I  Hydrophilic      - N and O that can donate and accept hydrogen bonds
                         (e.g., oxygen of hydroxyl group of Ser. or Thr)
  II  Acceptor         - N or O that can only accept a hydrogen bond
 III  Donor            - N that can only donate a hydrogen bond
  IV  Hydrophobic      - Cl, Br, I and all C atoms that are not in
                         aromatic rings and do not have a covalent bond to
                         a N or O atom
   V  Aromatic         - C in aromatic rings irrespective of any other 
                         bonds formed by the atom
  VI  Neutral          - C atoms that have a covalent bond to at least one
                         atom of class I or two or more atoms from class II
                         or III; atoms; S, F, P, and metal atoms in all cases
 VII  Neutral-donor    - C atoms that have a covalent bond with only one
                         atom of class III
VIII  Neutral-acceptor - C atoms that have a covalent bond with only 
                         one atom of class II
For each pair of contacts the state of legitimacy is shown below:

Legend:
+, legitimate
-, illegitimate
------------------------------------------------------------
  Atomic class           I  II  III   IV   V   VI  VII  VIII
------------------------------------------------------------
   I  (Hydrophilic)      +   +    +    -   +   +    +    +
  II  (Acceptor)         +   -    +    -   +   +    +    -
 III  (Donor)            +   +    -    -   +   +    -    +
  IV  (Hydrophobic)      -   -    -    +   +   +    +    +
   V  (Aromatic)         +   +    +    +   +   +    +    +
  VI  (Neutral)          +   +    +    +   +   +    +    +
 VII  (Neutral-donor)    +   +    -    +   +   +    -    +
VIII  (Neutral-acceptor) +   -    +    +   +   +    +    -
------------------------------------------------------------
Warning!
Atom classes for heterogroups are automatically assigned based on the atomic coordinates. However, in three cases (see below) the automatic assignment is currently ambiguous. In these cases, the user is advised to manually analyse the full list of contacts using LPC software.
1. Carbon atoms belonging to a 4-, 5- or 6-member ring are 
   considered "aromatic" (Class V) if the ring is approximately
   planar, and "hydrophobic" (Class IV) or "neutral" (Classes
   VI, VII, VIII) if the ring is non-planar.
2. The oxygen atom of a carbonyl or hydroxy group is considered
   "hydroxy" (Class I) if the CO bond is longer than 1.29 Å, and
   "carbonyl" (Class II) if shorter.
3. All nitrogen atoms are considered "hydrophilic" (Class I).

Please E-mail any questions and/or suggestions concerning this page to Vladimir.Sobolev@weizmann.ac.il